Boiler-furnace.



PATENTED MAR. 6, 1906.

S. P. PIERCE. BOILER FURNACE. I AFPLIO-ATION FILED NOV. 15, 1904;

3 SHEETS-SHEET l OOO No. 815073. PATENTED MAR. 6, 1906.

s. F. PIERCE.

BOILER FURNACE;

APPLICATION FILED NOV.15, 1904.

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. U m l lmhm W H U IW I L HHHHHTHHT b I I FIL FIIL FIIIII L I. n m H H 1 @m a m n iall No. 814,073. PATENTED MAR. 6, 1906.,

' s. F. PIERCE.

BOILER FURNACE.

APPLICATION FILED NOV. 15, 1904.

3 SHEETS-SHEET 3.

1 m lad SIMEON F; PIERCE, OF ST. PAUL, MINNESOTA.

BOILER-FURNACE.

Specification of Letters Patent.

:atented March 6, 1906.

Application filed November 15, 1904. Serial No. 232,773.

To (LU Lil/tom it may concern:

Be it known that I, SIMEoN F. PIERCE, a citizen of the United States, residing at St. Paul, in the county of Ramsey and State of Minnesota, have invented certain new and useful Improvements in Boiler-Furnaces, of which the following is a specification.

My invention relates to improvements in boiler-furnaces, and has for its object to provide improved means for supplying highlyheated air to the interior of the fire-box and for deflecting the flames in the combustion chamber up against the bottom of the boiler.

To this end the invention consists in the features of construction, combination, and arrangement of parts hereinafter described and claimed.

In the accompanying drawings, forming part of this specification, Figure 1 is a longitudinal section of a boiler-furnace embodying the invention, taken on line 0 o of Fig. 2. Fig. 2 is a horizontal section taken on line x a: of Fig. 1. Fig. 3 is a transverse vertical section through the fire-box, taken on line y y of Fig. 1; and Fig. 4 is a transverse vertical sec tion through the combustion-chamber, taken on line 2 2 of Fig. 1.

In the drawings, A represents the front wall, B B the side walls, C the rear wall, and D the bridge-wall, of the furnace.

E represents the fire-box in front of the bridge-Wall, and F the combustion-chamber at the rear of the brid e-wall.

G represents a boiler, of usual construction, supported between the side walls of the furnace.

It will be understood that in furnaces of this construction the flames and heated gases arising from the combustion of the fuel in the fire-box are carried back over the bridge-wall into the combustion-chamber beneath the rear portion of the boiler. This portion of the boiler being comparatively cool tends to cool the flames and deflect them downward away from it. To prevent this and to-direct the flames and heat up against the boiler, it is customary to fill up thespace between the bridge-wall and rear wall with earth or cinders. So long as this filling remains cool it will answer this purpose, for where flames pass between two surfaces of unequal temperature the flame will tend to avoid the cooler surface and seek the hotter surface; but in use the filling soon becomes so highly heated as to lose most of its efficiency in throwing the flames up against the boiler. In the present invention the air is introduced into the fire-box through a number of pipes leading from the outside air through the combustionchamber near the bottom of the boiler, the pipes being so. arranged and positioned in the combustion-chamber as to be exposed to the heat of the burning gases from the fire, and preferably to serve as deflectors to throw the flames in the combustion-chamber up against the bottom of the boiler, and so constructed and arranged as to discharge the air in great volume into the fire-box directly in front of the bridge-wall. In order to increase the expansion of the air passing through the pipes when these are subjected to the heat of the flames, and thereby to increase the force of the blast, I prefer to arrange the pipes so that their inlet ends or ports shall be near the bottom of the furnace, where the air is cooler than it is above. Thus the pipe 5 is shownled from the front, beneath the furnace, and up through the bottom of the combustion-chamber at the rear end thereof, nearly to the bottom of the boiler, and then extended forwardly to the bridge-wall, by which its discharge end is supported. Similarly, the pipes 6, which enter the combustion-chamber from the rear, are carried up nearly to the bottom of the boiler and thence extended forwardly and downwardly to the bridge-wall and have their inlet ends or ports near the floor of the furnace, the inlet ends in this case being carried rearwardly through the rear wall C of the furnace to the outside air. All of the pipes lead separately from the outside air, are supported near their discharge ends by the bridge-wall, and project inwardly from the bridge-wall into the interior of the fire-box. Those which enter the firebox at asufliciently high level are formed, preferably, with downturned discharge ends 3. To support the pipes within the combustion-chamber, a supporting-wall 7 may be arranged therein, as shown in the drawings. In order further to increase the force of the blast of air into the fire-box, the pipes are preferably made tapered or with a progressivelydecreasing diameter from the inlet end, where the sectional area is largest, to the discharge end, where it is smallest. the greatest heating benefit from the flames and gases passing back over the bridgewall, as well as to assist in deflecting the flames up against the bottom of the boiler, the air-pipes are arranged in close proximity To obtain IIO to the rear portion of the boiler and slant downwardly to the bridge-wall. They thus stand closer to the boiler at the rear of the combustionchamber than at the bridge wall, so that the flames from the fire-box will enter a sort of funnel and be thrown closer to the bottom of the boiler as they pass to the rear and become cooler. To secure the best results, the pipes are so arranged that the upper surface of the tier of pipes will follow approximately the curve of the boiler from side to side, the pipes at the side being higher up than the pipes in the middle, so that at any given point in the combustion-chamber all of the pipes will stand at a substantially uniform distance from the bottom of the boiler. It will be seen that by this arrangement the flames passing down upon and be tween the pipes will heat the pipes and the air which is passing through them on its way to the fire-box. This will cause the air in the pipes to expand, and by reason of the tapered shape of the pipes the air will be discharged with great force into the fire-box just in front of the bridge-wall, where it will mingle with and assist in consuming the products of combustion. It will also be seen that pipes arranged and constructed as shown accomplish the double purpose of discharging highlyheated air into the lire-box at the point where it will be most efficient and of deflecting the flames and heat of combustion up against the boiler, where they will heat the boiler and not be wasted. It will also be observed that the cooler air which enters the pipes prevents the pipes from becoming so heated as to lose their efiiciency in deflecting the flames to the boiler.

Various modifications may be made in the arrangement and construction of the pipes without departing from the principle of the invention, the scope of which is defined in the claims.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a furnace of the class described, the combination with the fire-box, bridge-wall, combustion-chamber and boiler, of a plurality of pipes leading from the outside air through the combustion-chamber near the bottom of the boiler to the fire-box, the pipes slanting downwardly from the rear portion of the boiler to the bridge-wall, and the discharge ends of the pipes being supported by the bridge-wall and discharging downwardly into the fire-box at the front side of the bridge-wall.

2. In a furnace of the class described, the combination with the fire-box, bridge-wall, combustion-chamber and boiler, of a plurality of air-pipes leading from the outside air through the combustion-chamber near the bottom of the boiler to the fire-box, the pipes being arranged to follow the periphery of the boiler from side to side so that all the pipes shall stand substantially the same distance from the boiler, the inlet ends of the pipes being positioned near the bottom of the furnace, and the outlet ends being supported by the bridge-wall and discharging into the firebox upon the front side of said bridge-wall.

3. In a furnace of the class described, the combination, with the fire-box, bridge-wall, combustion-chamber and boiler, of a plurality of pipes leading through the combustionchamber near the bottom of the boiler to the fire-box, said pipes being larger in diameter at the inlet end than at the outlet end, and being progressively reduced in diameter toward the outlet end.

4. In a furnace of the class described, the combination, with the fire-box, bridge-wall, combustion-chamber and boiler, of a plurality of air-pipes leading from the outside air through the combustion-chamber near the bottom of the boiler to the fire-box, the forward ends of the pipes being supported by the bridge-wall and being inclined downwardly into the fire-box.

5. In a furnace of the class described, the combination, with the fire-box, bridge-wall, combustion-chamber and boiler, of a plurality of air-pipes leading from the outside air through the combustion-chamber to the firebox, the inlet ends of the pipes being positioned near the bottom of the furnace, and the outlet ends being supported by the bridge-wall and discharging into the fire-box at the front side of the bridge-wall.

In testimony whereof I aflix my signature in presence of two witnesses.

SIMEON F. PIERCE.

I/Vitnesses:

ARTHUR P. LoTHRoP, EMILY F. Or'rs. 

